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f A n om l 0,6/ 9 7 W m m N7 o 7 s. k V w m m M s .U 4 E e t w a Ud ,m & 70 P S, E W) Mw hm, N 8 0MM SLM NRd wom IUFM HAM LD. L T U n K o 0 L Rw 5 n E HM 5 S e m W M i D O N m 7 MM w No. 625,398. Patented May 23, |899.

v H. JOHNSON. LDOKOUT- GLASS .FUR LOGUMOTWES, am.

(Application led Dec. 2B, 1897.)

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Tw: www; Pzvsua cc, Mmormwo. Msmlmm No. 625,398. Patented May 23,1899.

H. JDHNSON.

` LOKOUT GLASS FDR LUGOMDTIVES, &c.

(Application filed Dec. 2B, 1897.) (No Model.) V 4 Sheets--Sheet 3.

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N0. 625,393. Patented May 23, |899.

H. JUHNSON. LOOKUT -GLASS FOR LOCUMOTIVES, &c.

(Application led Dec. 28, 1897.)

4 Shets-Sheet 4.

(No Model.)

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ems mins on, wmourno.. msmnarm n c UNITED STATES PATENT OEEIOE.

HENRY JOHNSON, OF DUDLEY, ENGLAND. i

LOOKOuT-GLASS FOR LOCOMOTIVS, etc.

SPECIFICATION forming part of 'Letters Patent No. 625,398, dated May 23, 189e.

Application filed December 28, 1897. Serial No. 663,967. (No model.)

To zr/ZZ whom it may concern:

Be it known that I, HENRY JOHNSON, a subject of Her Majesty the Queen of Great Britain and Ireland, residing at Dudley, in the county of Wbrcester, England, have invented certain new and useful Improvementsiu Lookout Glasses for Locomotives, Steamboats, Lighthouses, and other Lookout Purposes, (for which I have obtained a patent in Great Britain, No. 2,047, bearing date January 29, 1895,) of which the following is a specification.

My invention has for its object so to construct and arrange the parts of lookoutglasses as to afford means for warming the said glasses, whereby snow is prevented from accumulating on or is immediately dislodged or melted from the weather side of the glasses and a clear lookout thus obtained for the engine-driver or person during falls of snow or snowstorms. The same object-namely, the dislodging of the snow from the lookoutglass-may also be effected by the other arrangement hereinafter described.

My improved lookout-glasses are particularly applicable to locomotives, and I will describe my invention as applied to a locomotive.

A lookout-glass constructed according to one of the arrangements of my invention consists, essentially, of two metallic circular or other frames placed edge to edge, each frame supporting a circular or other pane of glass, the two parallel panes of glass forming between them a steam-tight chamber. One of the said frames is Iixed to the weather-shield of the locomotive by snugs and screw-bolts, and the other or'outer frame is hinged at one side to the inner or fixed frame, so that the outer or movable frame can be opened from or closed upon the inner fixed frame on the weather-shield after the manner of a clockface frame. When the outer movable frame is closed upon the fixed inner frame, the two frames are secured together at the bottom by thumb-screws. The panes of glass are inserted in grooves or recesses, lined or packed with india-rubber, made in the inner faces of the two frames, and each pane is fixed in'its groove or recess bya lixing metallic ring secured by set-screws to the outside edge of each frame. By means of a packing-ring between each of the Outside iixed rings and the lined or packed recesses or grooves in which the panes are fitted the said panes are securely fixed in their places and rendered steam-tight by the securing of the said rings. In the bottom of the supporting-frames two passages are made, opening into the steamtight chamber formed between the two panes of the lookout-glass. By one of these passages dry steam is conducted to the chamber and by the other passage exhaust-steam or water of condensation is removed from the said chamber. By means of the steam-heated chamber between the two parallel panes the said panes are so heated that any snow accumulating on the weather side of the glass is immediately dislodged or melted.

Figure 1 of the accompanying drawings represents in front elevation and Fig. 2 invertical section, taken on the line A B, Fig. 1, the lookout-glass of a locomotive constructed according to this arrangement of my invention. Fig. 3 is a front elevation, and Fig. et a vertical section, of a modified form. Fig. 5 is a front view, and Fig. 6 a section, of still another form; and Figs. 7 and S are respectively a front view and section of a still further modification.

The same letters of reference indicate the same parts in all the figures.

a h are the metallic circular frames of the lookout-glass, placed edge to edge, supporting the two parallel panes of glass a2 b2, the said panes forming between them a steam-tight chamber c. The boiler side of the lookoutglass is marked D, and the foot-plate side is marked E. The metallic inner frame a is fixed to the weather-shield or cab-plate d by lugs and screw-bolts at f f', and the other or outer metallic frame b is hinged at e to the top (or side) of the fixed inner frame a. In place of the lugs for fixing the glass to the shield a .ange may be employed, as seen in the arrangements hereinafter described. Upon the hinge e the outer or movable carrying-frame b can be opened or closed upon the inner fixed frame a after the manner of the bezel of a clock. The two frames d b are secured together by the lugs and screws at f roo f. The panes of glass are inserted in grooves or recesses at g in' the two frames a b, and each pane is fixed in its supporting-frame by the outside ixing metallic ring h, securedby screw-pins t' c' to the principal frame or ring, as seen in the section Fig. 2. Before the panes are placed in the recess g and secured by the rings 7i 71, the said recesses are packed or lined with the packing-rings of india-rubber, (marked 70,) so that by the securing of the fixing-rings 7i h the panes are fixed in the recesses of the supporting-frames and rendered steam-tight.

Z m are two pipes or passages at the bottom of the lookout-glass frames a Z9, opening into the steam-tight chamber C between the two panes d2 b2. By the pipe or passage Z dry steam is conducted to the steam-tight chamber c, and by the other pipe or passage m exhaust-steam or water of condensation is removed from the said chamber. A pipe Z2,

fitted into the steam-passage Z and provided with a regulator-cock, conveys steam from the locomotive-boiler to the chamber c, and a pipe m2, fitted into the exhaust-passage m, provided with a regulator-cock, discharges the water of condensation.

By supplying steam to the chamber c, between the parallel panes of glass a2 b2, the said panes are maintained at such a temperature that in case of a snowstorm the snow is immediately dislodged or melted from or prevented from accumulating on the weather side of the lookout-glass and a clear lookout for the engine-driver obtained. By unfastening and opening the outer or movable pane-carrying frame Z2 access maybe obtained to the inside faces of the two panes a2 b2 for cleaning them.

Instead of the heating-chamber formed between the two parallel panes of the lookoutglass directly-that is,byadmitting dry steam into the said chamber*it.may be heated by a circular tube or coil of copper or by an annular channel at the circumferential part of the chamber, through which tube or coil or channel dry steam is made to circulate. In these cases the metallic frames of the panes of glass are modified either to receive the heating tube or coil or have formed in them the annular channel. The said metallic frames may also be constructed as to permit of both frames being opened toward the driver.

One of the last-described modifications of the lookout-glass is represented in front elevation in Fig. 3 and vertical section in Fig. 4. In this modified lookout-glass the outer frame is marked b and the inner frame a, and the parallel panes of glass carried by them b2 a2. The inside frame a is formed with a circumferential or annular recess p for receiving the circular copper tube or coil q by which the air-tight chamber c,between the two panes a2 b2, is heated. The lower ends of the heating tube or coil q within the chamber c are connected to steam-passages q2 g3 in the lower part of the inner frame a, a small hole (see dotted lines in Fig. 3) being made between the said steam-passages q2 Q3 and opening into the chamber c to serve as an outlet for moisture from the said chamber. The steam-passages (12 g3 are connected with the boiler by from which heats the chamber c and the panes a2 b2, the outer pane, or that exposed to the Weather, being maintained at a sufficiently high temperature to melt or dislodge snow or frost from it. B y fixing a steam-cock to each of the steam-pipes g4 and g5 a complete circulation of steam through the pipe or coil q may be obtained, and by shutting both cocks the pipe or coil may be rendered steamless during summer or when the heating apparatus is not required to be used. By the use of a third cock and blow-0E pipe and opening the same and closing one of the steam-cocks described steam may be blown through the coil into the atmosphere for cleansing the said coil. In this arrangement the panecarrying frame b is jointed or hinged at e to the panecarrying frame d and is fastened by the pin or bolt e2. 7L 7L are the metallic fixing-rings of the panes, and c' z' the fixing-pins.

Instead of fitting a copper'tube or coil in the circumferential recess of the lookout-glass frame, as last described and illustrated, the

copper tube or coil may be replaced by making in the circumferential part of the frame an annular steam heating-passage. This modification is represented in front elevation in Fig. 5 and Vertical section in Fig. G, where the annular steam heating-passage formed in the circumferential part of the frame is marked r. In this arrangement both of the pane-carrying frames a b are capable of opening toward the driver-that is, the inner frame a is hinged at d3 near the recessed part of the said frame d and is fastened at the bottom by the pin or bolt d4. Similarly the outer frame b is hinged at b3 and is fastened at the bottom by the pin or bolt b4. frame b is made sufficiently large to admit of the frame a being lifted through the opening made to receive the said frame Z), thereby affording the means of cleaning both sides of both panes from the foot-plate of the locomotive. The inner pane a2is secured to its frame by the fixing metal ring h and outer metal rim t, and the outer pane b2 is secured to its frame by the metal ring h2, as seen in the sectional view Fig. 6. frames may be properly spaced from each other, distance-pins s are provided, and thus in -closing the outer frame b these pins will arrest the frame b at the proper point for theA ready entry of the securing-pin b4. The distance-pins also prevent warping of the frames toward each other. The pins s are threaded into the frame Z1 and bear at their opposite extremities against the frame a.

parts of this lookout-glass do not differ in construction from those of the Varran gements Figs. 3 and et.

Fig. 7 represents in elevation, and Fig. S in vertical section ,another modification in which The other IOO It will be seen that the IIO In order that the hinged A the doublehinged arrangement of the frames is represented in combination with a copper heating tube or coil of the kind shown in Figs. 3 and 4.

Although I have described and represented my invention in connection with lookoutglasses having a circular igure, yet I wish it to be understood that my improvements may be applied to lookout-glasses having other and illustrated in the accompanying draw ings.

2. In a lookout-glass for locomotives, a pair of parallel pane-carrying frames, one of said frames being hinged for permitting access to the inner sides of said panes, and means for heating the space between said panes, substantially as described.

8. In a lookout-glass for locomotives, the combination with the window-casing of a pair of parallel pane-carrying frames of dierent size hinged thereto and opening in the same direction and a channel for heating fluid contained in the casing outside the limits of the smaller hinged frame, substantially as described. 4

In `Nitness whereof I have hereunto set my hand in presence of two Witnesses.

HENRY JOHNSON.

YWitnesses:

CHARLES BoswoRTH KETLEY, HERBERT WHITEHoUsE. 

